> How do you know what your ID number is? I cant find mine.  
 
There might be an easier way, but until someone chimes in with it, you need
to be a premium member, because you'll need to download a GPX file for a
cache that you own. Open that GPX file in a text editor and find the
character string "owner id=" (without the quotes). The number on the right
side of that equal sign is yours.
 
Steve
Team Tierra Buena